U.S. Pat. No. 3,275,815 describes umbrellas or parasols of this kind, in which the inside of the cover is illuminated by means of a single light-spreading device, the latter being supplied with light through a light conductor leading from the source of light, usually a battery-powered electric bulb situated in or near the handle of the umbrella or parasol. The use of a single light-spreading device has, however, proved insufficient to provide a reasonably uniform illumination of the whole of the inside of the cover.